The emergency power generator system you have in place is your insurance that the hospital, airport, government building, telecommunications facility, and even nuclear power plant that you manage will continue to operate in the event of a power failure. And just as you maintain business on a day-to-day basis, your on-call back up plan needs maintenance attention if it’s to serve you the moment you need it. Chances are good that you have diesel power behind your emergency generator. That’s because diesel engines make up the vast majority of the heavy lifting for standby power generators due to their reliability, durability and performance under load. Diesel generators can start and assume full-rated load in less than 10 seconds, and they typically can go 30,000 hours or more between major overhauls. This remarkable set of credentials is unique to diesel engines, but like any mechanical device, maintenance is critical for ensuring that a diesel powered standby generator will start and run when needed.
So, how should you plan for a maintenance schedule for your backup power system?
Because diesel engines are so durable, most maintenance is preventive in nature and it’s generally a good idea to establish and stick to a schedule of maintenance and service based on how often the generator is likely to be used and any operating conditions such as extreme temperatures in the environment. Important factors to consider in setting up a maintenance schedule are if the backup generator is on continuous duty and whether it has exposure to weather, salt water, dust, sand or other airborne contaminates.
There are six main areas of maintenance to cover to make sure the system is safe and reliable. Here are the basics of those areas:
General Inspection: This covers the exhaust system, fuel system, DC electrical system and the engine.
Lubrication Service: Check the engine oil level when it’s shut down and change the oil and filter at the intervals recommended.
Cooling System Service: Check the coolant level during shutdown periods. Heavy-duty diesel engines require a balanced coolant mixture of water, antifreeze and coolant additives. Be sure to inspect the exterior of the radiator for obstructions and remove all dirt or foreign material. Check the operation of the coolant heater.
Fuel System Service: Diesel fuel is subject to contamination and deterioration over time, and one reason for regular generator set maintenance is to use up stored fuel over the course of a year before it degrades. Fuel filters should be drained at regular intervals as well as checking for water vapor accumulation and condensation in the fuel tank. The charge-air piping and hoses should be inspected daily for leaks, holes, cracks or loose connections and the engine air intake components should be checked at regular intervals.
Starting Batteries: Weak or undercharged starting batteries are the most common cause of standby power system failures. Even when kept fully charged and maintained, lead-acid starting batteries are subject to deterioration over time and must be periodically replaced when they no longer hold a proper charge. Only a regular schedule of inspection and testing under load can prevent starting problems with the generator.
Diesel Generator Sets Exercise: Industrial Generator sets on continuous standby must be able to go from a cold start to being fully operational in a matter of seconds. This can impose a severe burden on engine parts. However, regular exercising keeps engine parts lubricated, prevents oxidation of electrical contacts, uses up fuel before it deteriorates, and, in general, helps provide reliable engine starting.
I’ve given you a few guidelines to consider for your planned diesel engine maintenance and perhaps alerted you to the importance of taking preventive action. Preventive maintenance for diesel engine generators plays a critical role in maximizing reliability, minimizing repairs and reducing long-term costs. By following generally recognized diesel maintenance procedures and specific manufacturer recommendations for your application, you’ll be assured that your standby power system will start and run when you need it most.
If you need more details, please click here to download our White Paper about Generator Sets Maintenance written by Timothy A. Loahlein, Project Manager at Cummins Power Generation.